The objectives of this project are (1) to assess psychophysical methods of experimental pain measurement, i.e., magnitude estimation, category scaling, and cross-modality matching. Pain will be experimentally induced by electrocutaneous, elecric tooth pulp, and mechanical heat stimulation; (2) to assess clinical pain measures, such as pain questionnaires and sensory matching methods, in a dental setting; (3) to determine the validity of experimental pain models by comparison of experimental and clinical pain responses; and (4) to evaluate known pharmacological and non-pharmacological pain-control agents. The recently-developed interactive computer-based scaling method was assessed in a study comparing the influence of he narcotic fentanyl on pain senasation evoked by contact heat. The method was very sensitive to the effects of fentanyl in relation to saline placebo. Fentanyl reduced pain intensity 2 min after administration and reached a peak effect by 11 min. The studies of a verbal-descriptor clinical pain measure continued with the development of a linear variance measure of scaling performance. Poor performers were identified; eliminating these invalid profiles improved the psychometric properties of the scales and increased their sensitivity to a narcotic analgesic. A new study quantified the magnitude of descriptor phrases of pleasantness and unpleasantness by ratio scaling procedures. Preliminary results show that adverbs modify adjectives by relatively constant amounts independent of the adjective, suggesting that verbal scales can be constructed without extensive psychometric development. A new series of studies is assessing nonpharmacological methods of pain control. Preliminary results show that analgesia to experimental stimuli following hypnotic suggestion varies with the type of experimental measure and assessment methods.